Doors are generally closed after they are opened. However, it is often necessary to keep a door open depending on the situation. It is more practical to keep open the door of a passage where many people come and go so as to avoid frequently opening and closing the door each time a person passes through. By keeping such a door open, the door can be protected from damage to the hinges as there is applied no load thereon. It is also possible to prevent noises of opening/closing the door if the door is in a passage with frequent comings and goings, and to keep the environment quiet.
It is further advantageous to keep open a door for a delivery entrance. The delivery person is freed from the trouble of putting the goods down on the floor, opening the door, and then lifting the goods again to pass through the door. This putting down and lifting of a load to open the door becomes all the more necessary if the delivery person is carrying a huge or heavy load.
It is also advantageous to keep a door open where ventilation of a room is called for. Such a door may be a door to an entrance hall, to a kitchen, or to another room. Adjoining rooms can be connected and turned into a larger room by keeping the doors open to such rooms, and children playing in the next room can be watched.
In order to achieve such states as mentioned above, a wedge shaped stopper is often placed between the lower edge of the open door and the floor, or a string is tied to the door knob and stretched to keep the door open. Another measure generally taken to keep a door open is to provide a hook on the floor of which the direction can be changed into different directions and to engage said hook with a ring mounted on the door surface.
All these methods are defective in that the wedge shaped stopper must be placed or taken out, the string must be tied or un-tied, or the hook engaged or disengaged every time the door is to be kept open. In order to avoid such troublesome steps, a door is merely left open and no wedge-like stoppers, strings or hooks are used. However, such a door often becomes shut by the wind, emitting loud noise.
A need for a means for keeping a door open by a simple manipulation was thus keenly felt. The door stopper according to the present invention was conceived in view of situations as outlined above.